1. Field of the Invention
The present invention relates to a rolling bearing unit having a sensor.
2. Related Art
The rolling bearing unit for a wheel described in JP-A-2007-127253 is a conventional rolling bearing unit having a sensor.
In this rolling bearing unit for a wheel, two rows of inductance type displacement sensors are arranged in the axial direction and three translation loads and two moment loads of the rolling bearing unit for a wheel are calculated.
In the above circumstances, the following problems may be encountered. The inductance type displacement sensor needs a large space in which it is arranged. Therefore, it is difficult to reduce a size of the rolling bearing unit for a wheel.
Further, a signal sent from the displacement sensor is outputted to a signal processing portion, which is located on the opposite side to the rolling element side of the cap member with respect to the cap member, through a signal line penetrating the cap member which is arranged so that one end portion in the axial direction of the inner shaft 1 can be covered with the cap member.
In the circumstances described above, in the rolling bearing having a sensor, it is desired to reduce noise contained in the signal.